Carnot battery: Simulation and design of a reversible heat pump-organic Rankine cycle pilot plant

The steady growing demand of further storage capacity for the compensation of the daily fluctuations of renewable energies in national energy grids requires the development of new scalable energy storages. Pumped Thermal Energy Storages (PTES) like reversible heat pump - organic Rankine cycle systems are a possible candidate for this. In this work, the complete process from initial cycle design and fluid selection to the component selection and CAD work of the demonstrator is shown. For the simulation of the cycles, a stationary Matlab model was used. A screening of various suitable fluids was performed and four promising fluids were selected for further investigation. Out of these four fluids, R1233zd(E) was selected as final candidate for the demonstrator. The simulated power-to-power efficiency (eta(P2P)) of the system reaches up to 59% for the design case. With the simulated data, the apparatus selection was performed and a CAD model was developed to build the demonstrator as a laboratory scale plant with 14.7 kW electrical compressor power.

Automated summary

This study presents the design and development process of a Pumped Thermal Energy Storage system, identifying the final candidate for the demonstrator. Simulated data shows the system's power efficiency of up to 59%.